Laravel Problem credentials do not match our records

First of all Sorry for my bad english.

I am new to laravel. I have recently run into some problems with authentication/login system which comes built-in in laravel by the command make:auth.

The registration process is working correctly and after that it logs me in automatically. but when I log out and try to log back in, I get this error:

These credentials do not match our records.

I'm not sure whats wrong! but i tried to search error on google stack overflow and etc. The solution i found is this. These credentials do not match our records, laravel 5.2 but it also didn't work.

This is my code.

Http/Auth/LoginController.php

<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;


class LoginController extends Controller
{

    use AuthenticatesUsers;


    protected $redirectTo = '/home';

    public function __construct()
    {
        $this->middleware('guest')->except('logout');
    }


}

This is model

User.php

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    protected $fillable = [
        'user_name', 'email','user_password','user_created_by',
    ];

    protected $hidden = [
        'user_password', 'remember_token',
    ];

    protected $primaryKey = 'user_id';

    public function setPasswordAttribute($password)
    {
        $this->attributes['password'] = bcrypt($password);
    }
}

This is View

Views/auth/login.blade.php

@extends('layouts.app')

@section('content')
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <div class="panel panel-default">
                <div class="panel-heading">Login</div>

                <div class="panel-body">
                    <form class="form-horizontal" method="POST" action="">
                        

                        <div class="form-group">
                            <label for="email" class="col-md-4 control-label">E-Mail Address</label>

                            <div class="col-md-6">
                                <input id="email" type="email" class="form-control" name="email" value="" required autofocus>

                                @if ($errors->has('email'))
                                    <span class="help-block">
                                        <strong></strong>
                                    </span>
                                @endif
                            </div>
                        </div>

                        <div class="form-group">
                            <label for="password" class="col-md-4 control-label">Password</label>

                            <div class="col-md-6">
                                <input id="password" type="password" class="form-control" name="password" required>

                                @if ($errors->has('password'))
                                    <span class="help-block">
                                        <strong></strong>
                                    </span>
                                @endif
                            </div>
                        </div>

                        <div class="form-group">
                            <div class="col-md-6 col-md-offset-4">
                                <div class="checkbox">
                                    <label>
                                        <input type="checkbox" name="remember" > Remember Me
                                    </label>
                                </div>
                            </div>
                        </div>

                        <div class="form-group">
                            <div class="col-md-8 col-md-offset-4">
                                <button type="submit" class="btn btn-primary">
                                    Login
                                </button>

                                <a class="btn btn-link" href="">
                                    Forgot Your Password?
                                </a>
                            </div>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
</div>
@endsection

This is User Table

User Table

via Chebli Mohamed